[viruses]
   Family Papillomaviridae
     Subfamily Firstpapillomavirinae
       Genus Betapapillomavirus
         1 Betapapillomavirus 1ᵀ
         2 Betapapillomavirus 2
         3 Betapapillomavirus 3
         4 Betapapillomavirus 4
         5 Betapapillomavirus 5
         6 Betapapillomavirus 6